The present invention relates to an inspecting apparatus for inspecting the mounting state of an electronic component or the printing state of a cream solder on an electronic component mounting line.
With the recent trend toward mounting of small electronic component chips on a printed circuit board, it has become difficult to visually inspect the mounting state of the electronic component or the printing state of a cream solder of the electronic component by relying on the naked eye of an operator. Accordingly, as depicted below, an inspecting apparatus is used for inspecting the printing state of cream solder.
In a conventional system shown in FIG. 19, the mounting state of each printed circuit board 2 supplied from a precedent process (a printing apparatus of a cream solder) 1 is inspected by an inspecting apparatus 3. Non-defective ones and defective ones are respectively sent to a subsequent process 4 and a printed circuit board stockroom 5.
The inspecting apparatus 3 measures the area of the cream solder, etc. (mounting position, etc. in the case where the precedent process is a mounting apparatus of an electronic component), thereby deciding, as shown in FIG. 6, that those in the allowable range are good or non-defective (represented by (g)) and those outside the allowable range are not acceptable (indicated by (b)), on the basis of a preset absolute decision criterion (A).
In the above example, however, since the decision of the inspecting apparatus 3 is based only on the absolute decision criterion (A), it is difficult to know the operating state of the apparatus in the precedent process and to predict a dangerous state.
People skilled in the technical field may be able to devise an inspecting method of enabling the detection and monitoring of the operating state of the apparatus in the preceding process 1 on the basis of all the data measured by the inspecting apparatus 3. However, in such a method it takes a long time to process all the data, therefore the method suffers a drawback in that a dangerous condition cannot be rapidly predicted based on data obtained in the precedent process in a mass production system.